docs(firehose-protos, forrestrie): update protobufs docs

crates/firehose-protos/README.md

@@ -1,9 +1,8 @@
 # `firehose-protos`
 
-StreamingFast's and Pinax's Rust-compiled protocol buffers for Firehose,
-used in [header-accumulator](./../header-accumulator/Readme.md),
-[flat-files-decoder](./../flat-files-decoder/Readme.md), and
-[forrestrie](./../../README.md).
+StreamingFast's Firehose protocol buffers compiled to Rust,
+used in [header-accumulator](./../header-accumulator/Readme.md)
+and [flat-files-decoder](./../flat-files-decoder/Readme.md).
 
 ## Protobuffer definitions
 

crates/forrestrie/protos/README.md

@@ -0,0 +1,5 @@
+# Protobuffer definitions
+
+## [`type.proto`](https://github.com/pinax-network/firehose-beacon/blob/main/proto/sf/beacon/type/v1/type.proto)
+
+Pinax's Firehose Beacon `Block` implementation.